I'm trying to make inkscape a simple level editor for my team-mates but I'm kinda stuck on the transform attribute.Basically we only use circles to position items, and I want to use the sodipodi:- rx ry cx cy properties. As I move them around they do not change, only the Matrix does ( I guess thats kinda logical).But I need to get the position from cx cy and the radius from rx and ry. I have no idea how to apply the matrix to it. Yes I did read the official site on matrices.

Also I have just noticed that this does not take into account skew... Not sure on that. I think you may not be able to get the skew value out though. 7 degrees of freedom (tx,ty,rotation,sx,sy,skew x, skew y)? and 6 variables...

It looked like I already got the scaling right. I just simply multiplied the sx and sy with rx and ry. I didn't use the Pythagorean theorem(?) though...not sure if that will bite me later on.But the translations don't make sense at all...